package com.mango.iot.gateway.tcp.utils;

/**
 * ItuUtil
 *
 * @author liangfeihu
 * @since 2021/3/31 下午3:26
 */
public class CrcItuUtils {
    private static char[] crcTable = {
            0X0000, 0X1189, 0X2312, 0X329B, 0X4624, 0X57AD, 0X6536, 0X74BF,
            0X8C48, 0X9DC1, 0XAF5A, 0XBED3, 0XCA6C, 0XDBE5, 0XE97E, 0XF8F7,
            0X1081, 0X0108, 0X3393, 0X221A, 0X56A5, 0X472C, 0X75B7, 0X643E,
            0X9CC9, 0X8D40, 0XBFDB, 0XAE52, 0XDAED, 0XCB64, 0XF9FF, 0XE876,
            0X2102, 0X308B, 0X0210, 0X1399, 0X6726, 0X76AF, 0X4434, 0X55BD,
            0XAD4A, 0XBCC3, 0X8E58, 0X9FD1, 0XEB6E, 0XFAE7, 0XC87C, 0XD9F5,
            0X3183, 0X200A, 0X1291, 0X0318, 0X77A7, 0X662E, 0X54B5, 0X453C,
            0XBDCB, 0XAC42, 0X9ED9, 0X8F50, 0XFBEF, 0XEA66, 0XD8FD, 0XC974,
            0X4204, 0X538D, 0X6116, 0X709F, 0X0420, 0X15A9, 0X2732, 0X36BB,
            0XCE4C, 0XDFC5, 0XED5E, 0XFCD7, 0X8868, 0X99E1, 0XAB7A, 0XBAF3,
            0X5285, 0X430C, 0X7197, 0X601E, 0X14A1, 0X0528, 0X37B3, 0X263A,
            0XDECD, 0XCF44, 0XFDDF, 0XEC56, 0X98E9, 0X8960, 0XBBFB, 0XAA72,
            0X6306, 0X728F, 0X4014, 0X519D, 0X2522, 0X34AB, 0X0630, 0X17B9,
            0XEF4E, 0XFEC7, 0XCC5C, 0XDDD5, 0XA96A, 0XB8E3, 0X8A78, 0X9BF1,
            0X7387, 0X620E, 0X5095, 0X411C, 0X35A3, 0X242A, 0X16B1, 0X0738,
            0XFFCF, 0XEE46, 0XDCDD, 0XCD54, 0XB9EB, 0XA862, 0X9AF9, 0X8B70,
            0X8408, 0X9581, 0XA71A, 0XB693, 0XC22C, 0XD3A5, 0XE13E, 0XF0B7,
            0X0840, 0X19C9, 0X2B52, 0X3ADB, 0X4E64, 0X5FED, 0X6D76, 0X7CFF,
            0X9489, 0X8500, 0XB79B, 0XA612, 0XD2AD, 0XC324, 0XF1BF, 0XE036,
            0X18C1, 0X0948, 0X3BD3, 0X2A5A, 0X5EE5, 0X4F6C, 0X7DF7, 0X6C7E,
            0XA50A, 0XB483, 0X8618, 0X9791, 0XE32E, 0XF2A7, 0XC03C, 0XD1B5,
            0X2942, 0X38CB, 0X0A50, 0X1BD9, 0X6F66, 0X7EEF, 0X4C74, 0X5DFD,
            0XB58B, 0XA402, 0X9699, 0X8710, 0XF3AF, 0XE226, 0XD0BD, 0XC134,
            0X39C3, 0X284A, 0X1AD1, 0X0B58, 0X7FE7, 0X6E6E, 0X5CF5, 0X4D7C,
            0XC60C, 0XD785, 0XE51E, 0XF497, 0X8028, 0X91A1, 0XA33A, 0XB2B3,
            0X4A44, 0X5BCD, 0X6956, 0X78DF, 0X0C60, 0X1DE9, 0X2F72, 0X3EFB,
            0XD68D, 0XC704, 0XF59F, 0XE416, 0X90A9, 0X8120, 0XB3BB, 0XA232,
            0X5AC5, 0X4B4C, 0X79D7, 0X685E, 0X1CE1, 0X0D68, 0X3FF3, 0X2E7A,
            0XE70E, 0XF687, 0XC41C, 0XD595, 0XA12A, 0XB0A3, 0X8238, 0X93B1,
            0X6B46, 0X7ACF, 0X4854, 0X59DD, 0X2D62, 0X3CEB, 0X0E70, 0X1FF9,
            0XF78F, 0XE606, 0XD49D, 0XC514, 0XB1AB, 0XA022, 0X92B9, 0X8330,
            0X7BC7, 0X6A4E, 0X58D5, 0X495C, 0X3DE3, 0X2C6A, 0X1EF1, 0X0F78,
    };

    /**
     * 计算给定长度数据的 16 位 CRC
     */
    public static char getCrc16(byte[] pData, int nLength) {
        int i = 0;
        // 初始化
        char fcs = 0xffff;
        while (nLength > 0) {
            fcs = (char) ((fcs >> 8) ^ crcTable[(fcs ^ pData[i]) & 0xff]);
            nLength--;
            i++;
        }
        // 取反
        return (char) ~fcs;
    }

    public static boolean checkCrc(int packetType, int packageLength, byte protocolNumber, byte[] dataContent, byte[] seqNum, byte[] crcData) {
        byte[] checkData = new byte[packetType + 1 + dataContent.length + 2];
        checkData[0] = (byte) (packageLength & 0xFF);
        if (packetType == 2) {
            checkData[0] = (byte) ((packageLength >> 8) & 0xFF);
            checkData[1] = (byte) (packageLength & 0xFF);
        }
        checkData[packetType] = protocolNumber;

        int gap = packetType + 1;
        int len = dataContent.length;
        for (int i = 0; i < len; i++) {
            checkData[i + gap] = dataContent[i];
        }
        checkData[len + gap] = seqNum[0];
        checkData[len + gap + 1] = seqNum[1];

        return checkCrc(crcData, checkData);
    }

    public static boolean checkCrc(byte packageLength, byte protocolNumber, byte[] dataContent, byte[] seqNum, byte[] crcData) {
        byte[] checkData = new byte[1 + 1 + dataContent.length + 2];
        checkData[0] = packageLength;
        checkData[1] = protocolNumber;
        int len = dataContent.length;
        for (int i = 0; i < len; i++) {
            checkData[i + 2] = dataContent[i];
        }
        checkData[len + 2] = seqNum[0];
        checkData[len + 3] = seqNum[1];

        return checkCrc(crcData, checkData);
    }

    private static boolean checkCrc(byte[] crcData, byte[] checkData) {
        char crc16 = getCrc16(checkData, checkData.length);
        byte one = (byte) ((crc16 >> 8) & 0xff);
        byte two = (byte) (crc16 & 0xff);
        boolean flag = (one == crcData[0]) && (two == crcData[1]);
        return flag;
    }

    public static boolean checkCrc(byte packageLength, byte protocolNumber, byte[] seqNum, byte[] crcData) {
        byte[] checkData = new byte[]{packageLength, protocolNumber, seqNum[0], seqNum[1]};
        return checkCrc(crcData, checkData);
    }

    public static void main(String[] args) {

        byte[] login = new byte[]{0x11, 0x01, 0x07, 0x52, 0x53, 0x36, 0x78, (byte) 0x90,
                0x02, 0x42, 0x70, 0x00, 0x32, 0x01, 0x00, 0x05};
        System.out.println(login.length);
        char crcLogin = getCrc16(login, login.length);

        //crc[0]
        byte one = (byte) ((crcLogin >> 8) & 0xff);
        System.out.println(Integer.toHexString(one & 0xFF).toUpperCase());
        //crc[1]
        byte two = (byte) (crcLogin & 0xff);
        System.out.println(Integer.toHexString(two & 0xFF).toUpperCase());

        String str = Integer.toHexString(two | 0xffffff00).toUpperCase();
        System.out.println(str);
        System.out.println(str.substring(6));

    }

}
